Before We Are Born: Essentials of Embryology and Birth Defects by Keith L. Moore and T.V.N. Persaud: This textbook provides a concise and readable overview of human embryology, focusing on birth defects.
Human Embryology by T.W. Sadler: This free online textbook covers the entire range of human embryology, from conception to birth. It includes high-quality images and diagrams, as well as interactive exercises and quizzes.
Cardiac Embryology By Ra-id Abdulla, MD.Includes animations, notes, pictures, and questions.
The Multi-Dimensional Human Embryo By the University of Michigan.
Preview the unique changes in human embryos by weeks.
Good navigational online book on embryology written by Dr. Mark Hill
17 lectures on developmental anatomy with simple illustrations and explanations.